1. Field of the Invention
The present invention relates to an electrical connector. More specifically, the present invention relates to a low insertion force electrical connector with a high density of, and a large number of, contacts.
2. Brief Description of Earlier Developments
Improvements in computer systems and communications equipment generally involve miniaturization and increased operating speeds. Designers must adapt the electrical connectors used in these systems to handle such changes.
Several types of electrical connectors exist that have adapted to miniaturization and to the increased operating speeds. One type is a zero insertion force (ZIF) connector. ZIF connectors use a mechanism either to spread a contact apart before receiving its mating contact or to provide mechanical advantage to a contact so that it may spread apart and engage its mating contact.
While beneficial in larger applications, current ZIF designs may not be preferred in high contact density situations. ZIF connectors can be complex and costly, particularly when miniaturization is required. In addition, the smaller actuators may not have sufficient strength to spread a contact apart or to mate the contacts. The actuators also may not fit within footprint limitations. Finally, ZIF connectors may not provide sufficient contact wipe to ensure a stable electrical contact.
Another type of electrical connector uses contacts with differential heights. Some of the contacts reside at one elevation, while the others reside at a different elevation. The taller contacts mate first, followed by the shorter contacts. As a result, the connector exhibits a lower peak insertion force. The peak insertion force is lower because not all of the connectors mate in parallel (i.e. at the same time).
Connectors with differential height contacts, however, may not be preferred in high contact density situations. In miniaturized connectors, producing differential height contacts are viewed as impractical, and are likely to be unsuccessful.